/**
83. 删除排序链表中的重复元素
 * }
 */
/**
 * @param {ListNode} head
 * @param {number} val
 * @return {ListNode}
 */
var removeElements = function(head) {
    let curr = head
    while(curr&&curr.next) {
      if(curr.val==curr.next.val) { //如果是删除指定元素， 对比curr.val==val
        curr.next = curr.next.next
      }else {
        curr = curr.next
      }
    }
    return head
};